{"id":6505,"date":"2013-08-16T15:41:12","date_gmt":"2013-08-16T22:41:12","guid":{"rendered":"http:\/\/planets.ucla.edu\/?p=6505"},"modified":"2021-01-18T01:36:10","modified_gmt":"2021-01-18T09:36:10","slug":"ucla-scientists-study-magnetic-fields-around-earth-to-forecast-space-weather","status":"publish","type":"post","link":"http:\/\/planets.ucla.edu\/?p=6505","title":{"rendered":"UCLA scientists work to forecast space weather"},"content":{"rendered":"
\"\"<\/a>
The THEMIS spacecraft in orbit around the Earth. Image Credit: SVS\/NASA<\/figcaption><\/figure>\n

The Sun is a veritable force in our solar system.\u00a0 It emits a tremendous amount of heat and energy, called the solar wind, which constantly blows and buffets the planets at a velocity almost two thousand times faster than the average jet plane.\u00a0 Akin to an invisible shield, the Earth\u2019s magnetic field deflects most of the solar wind, but it happens often that the magnetic fields of the Earth and Sun briefly and directly come into contact with one another.<\/p>\n

When the fields connect, part of Earth\u2019s magnetic field \u201cpeels away from the sunward side and drapes around the back of the planet,\u201d said sixth-year graduate student, Christine Gabrielse.\u00a0 The backside of Earth\u2019s magnetic field, or magnetotail, is \u201csqueezed from the outside as a result of the peel back,\u201d she said.\u00a0 Eventually, two points on the interior of the Earth\u2019s magnetic field meet in what is called a near-Earth reconnection, releasing a great deal of energy that flows toward Earth.\u00a0 \u201cThese powerful phenomena, known as substorms, can create more than picturesque auroras\u201d, Gabrielse said. \u201cThey can damage spacecraft or astronauts, or even ground-based systems.\u201d\u00a0 On March 13th, 1989, one such storm caused a legendary power outage in Canada\u2019s Quebec province that left more than three quarters of a million people without power for nearly twelve hours.<\/p>\n

While scientists had studied substorms for years, many questions remained regarding these space weather events.\u00a0 Proposed by UCLA Professor Vassilis Angelopoulos, NASA\u2019s Time History of Events and Macroscale Interactions During Substorms (THEMIS) mission was designed to answer some of these questions.<\/p>\n

Launched in February 2007, the mission consisted of five identical satellites deployed to critical locations around Earth.\u00a0 Unprecedented at the time, THEMIS allowed scientists to track the flow of energy around Earth and determine how and where substorms initiate.\u00a0 \u201cThe spacecraft gave us five pinholes in the magnetic curtain we are trying to see through,\u201d said Drew Turner, an assistant researcher at UCLA working on the THEMIS mission.<\/p>\n

From their unique orbits, engineered to simultaneously provide five key perspectives of the vast space environment, the spacecraft quickly solved the questions they\u2019d set out to answer. \u201cIn 2008, THEMIS repeatedly showed that reconnection happens in the magnetotail first, activating a substorm,\u201d said Gabrielse.\u00a0 With its primary goal accomplished, THEMIS set new objectives.\u00a0 Splitting the satellites into two groups, three continued to orbit Earth, while two were sent to the Moon as a \u2018new\u2019 mission called Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon\u2019s Interaction with the Sun (ARTEMIS).\u00a0 \u201cThe extension to ARTEMIS was quite miraculous,\u201d said Turner.\u00a0 \u201cThe spacecraft were not equipped with the ability to maneuver out of their orbit.\u00a0 The THEMIS engineers and operators sent satellites to the Moon by way of tiny puffs of rocket fuel.\u201d<\/p>\n

Using \u201cthe most comprehensive plasma instruments we\u2019ve sent to the Moon,\u201d the two ARTEMIS satellites are now busy determining the rock types on its surface, said Turner.\u00a0 The satellites detect small variations in the Moon\u2019s particle and electric fields allowing them to distinguish between different materials.\u00a0 \u201cIt\u2019s a natural way of detecting surface composition from afar,\u201d said Turner.\u00a0 In addition, the satellites are improving substorm research by studying the Earth\u2019s space environment from their entirely new viewpoint near the Moon.\u00a0 \u201cWith the two spacecraft at the Moon we can test what\u2019s happening on the other side of the reconnection,\u201d said Shanshan Li, a fifth-year UCLA graduate student.\u00a0 \u201cWe can start to form a three-dimensional substorm model of Earth\u2019s space environment.\u201d<\/p>\n

The THEMIS satellites that have remained in orbit around Earth are \u201cscientific goldmines,\u201d according to Turner.\u00a0 Coordinating observations with the Van Allen Probes, a pair of recently launched NASA satellites, they were able to detect a previously unknown layer of charged particles surrounding Earth.\u00a0 Turner said, \u201cin a huge and complex system, my bread and butter is combining as many satellites\u2019 data as I can to get as complete a global picture as possible.\u201d<\/p>\n

With the Sun approaching a period of increased activity, the media have begun to report space weather more often.\u00a0 \u201cIt\u2019s good to see that society is taking an interest,\u201d said Turner. \u201cWe\u2019ve become increasingly dependent on space-based assets,\u201d said Turner. \u201cEven something as simple as using an ATM will most often result in a satellite-relayed signal at some point.\u201d Since large space storms can have huge societal impacts, it is important to be able to see them coming.\u00a0 \u201cJust like meteorologists want to be able to forecast a storm on Earth, we want to be able to predict a storm in space,\u201d said Gabrielse. \u201cUltimately, our aim is to determine what\u2019s going on in the Sun-Earth environment and try to better understand it.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"

The Sun is a veritable force in our solar system.\u00a0 It emits a tremendous amount of heat and energy, called the solar wind, which constantly blows and buffets the planets at a velocity almost two thousand times faster than the average jet plane.\u00a0 Akin to an invisible shield, the Earth\u2019s magnetic field deflects most of … <\/p>\n

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